Ladders tend to be unstable for a variety of reasons which are inherent in their design and use. To be practical, ladders must be portable and thus lightweight. Most ladder induced injuries are caused by the ladder shifting relative to the underlying support surface, such as may occur when the ground surface is uneven or soft. Relatively few injuries occur from simple tipping of folding ladders because the area of the base is surprisingly large. Usually, tipping is caused by an irregularity in the underlying surface or some softness in the underlying surface as the user applies weight to the ladder. It is accordingly not surprising that auxiliary props or supports have been applied to ladders for the purpose of increasing stability.
A typical auxiliary support includes a strut pivoted to the ladder, typically near the top in a folding ladder or near the middle in a straight or leaning type ladder. The strut is pivoted for movement between a stowed position adjacent the ladder frame and an extended position defining an acute angle with the ladder. Often, the auxiliary support can be telescoped, i.e. extended or retracted in an axial direction, to contact the underlying ground surface and provide additional stability. It is to this type device that this invention most nearly relates. Typical auxiliary supports for ladders are found in U.S. Pat. Nos. 2,997,127 and 3,901,354. Other disclosures of interest are found in U.S. Pat. Nos. 468,987 and 1,890,423.